Dice vegetables such as onion, bell pepper, potato, and carrot.
Drizzle olive oil in a pan and sauté the vegetables.
Add tomato sauce, salt, and pepper, and bring to a boil.
Place boiled potatoes or pasta in an oven-safe dish.
Pour the vegetable tomato sauce over them.
Generously top with mozzarella cheese.
Bake in the oven at 200°C for about 12 minutes.